One non-exclusive application of such a separator is in the production of petroleum oil. In this application, which is of particular interest to the inventors without this being considered as limiting, the separator is placed in an oil well for example. It receives a fluid comprising water and oil coming from an oil-producing reservoir, and extracts oil having a reduced water content. The water separated from the extracted oil is reinjected into a reservoir level, possibly different from the producing reservoir, without any need for it to be separated or processed in a topside facility. One variant is to separate the fluids in the well and bring them to the surface.
Cyclonic flow conditions in a chamber for separating the components of a fluid are particularly effective for separating the components by weight. At the outlet from the cyclonic flow separation chamber, the heavier components are collected at a radial position that is further from the center than the lighter components. In an ideal cyclonic flow, the tangential velocity of the particles in the fluid medium increases in a hyperbolic relationship from the periphery of the chamber to a radius where it reaches a maximum value, and then decreases between said radius and the center of the chamber in a linear relationship. It is zero at the center of the separation chamber. This subjects the particles of the fluid medium to radial accelerations in the hyperbolic zone that are inversely proportional to the cube of the radius.
Documents FR-A-2 592 324 and FR-A-2 919 206 describe separators for heterogeneous liquids having a cylindrical separation chamber and an axial impeller which rotate together around their common axis. The impeller has a core with guide channels around it that bring a fluid medium into the chamber in order to generate a cyclonic flow.
These separators allow separating two fluid components of the fluid medium. However, when the medium is also loaded with solid particles that are denser than the fluid components, these accumulate on the inner wall of the separation chamber, particularly near the downstream end of the separation chamber. This accumulation interferes with the cyclonic flow, and causes erosion of the downstream end of the separation chamber.
An object of the invention is to improve rotary-type cyclonic flow separators. In particular, removal of the solid particles from the fluid medium in the separation chamber is desired.